A polybutylene succinate and polysiloxane block copolymer and a method for preparing the same

Abstract

The application provides a polybutylene succinate and polysiloxane block copolymer and a preparation method thereof, and solves the problems of low impact strength and lack of functionality of a polybutylene succinate homopolymer by introducing a polysiloxane block with good biocompatibility, good biostability and wide sources into the polybutylene succinate to prepare the polybutylene succinate and polysiloxane block copolymer. The polybutylene succinate and polysiloxane block copolymer has excellent mechanical properties and high molecular weight, the polysiloxane block also endows the block copolymer with good stain resistance and excellent impact resistance, and meanwhile improves the tensile strength, bending strength and elongation at break of the block copolymer.

Description

Technical Field

[0001] This invention relates to the field of polymer synthesis, and more particularly to a polybutylene succinate and polysiloxane block copolymer and its preparation method. Background Technology

[0002] The white pollution caused by traditional plastics has spurred the rapid development of biodegradable plastics. Among numerous biodegradable polymer materials, polybutylene succinate (PBS) has attracted widespread attention due to its excellent comprehensive properties and is one of the most promising biodegradable materials.

[0003] Melting point of polybutylene succinate (PBS) T m The temperature is 110-116℃, and the thermal decomposition temperature is higher than ( T d With a temperature above 350℃, polybutylene succinate (PBS) exhibits good thermal stability, and its mechanical properties are close to those of low-density polyethylene (LDPE) and polypropylene (PP), meeting the requirements for general-purpose plastics. Furthermore, PBS is stable in dry environments and can be completely degraded in composting conditions. However, compared to other traditional non-degradable polymers, PBS still suffers from drawbacks such as high price, lack of functionality, and poor mechanical properties, particularly its poor impact strength, making it difficult to meet the performance requirements of practical applications. Therefore, designing biodegradable material molecular structures and introducing copolymerization units to improve the various properties of PBS and endow it with functionality has become a current research focus. Random copolymerization is simple and easy to implement and is often used for copolymer modification of polymers. However, random copolymerization disrupts the molecular chain structure of PBS, reducing the polymer's crystallinity. While improving the material's impact resistance, it significantly negatively impacts the material's crystallinity, significantly reducing its melting point, tensile strength, and flexural strength. Block copolymers can combine the advantages of both homopolymers without compromising the crystallinity of the crystalline segments, causing a significant decrease in crystallinity, or sacrificing the material's thermal and mechanical properties. Currently, polybutylene succinate block copolymers are mainly synthesized using polyether molecular chains with succinic acid and butanediol. However, the large number of ether bonds in the polyether blocks significantly reduces the thermal stability of the polyester material. Furthermore, the flexibility of the polyether segments drastically reduces the tensile and flexural strength of the product.

[0004] Compared to polyether blocks, polysiloxanes exhibit excellent thermal stability and oxidation resistance due to their unique organic and inorganic structures, as well as outstanding chemical inertness, low-temperature resistance, anti-icing properties, biocompatibility, and biostability. Previous studies have reported the modification of polycarbonate, polyurethane, and petroleum-based polyesters by introducing polysiloxane segments with different side groups and end groups. CN115124707 A discloses a method for modifying polycarbonate with phosphorus-containing polysiloxanes. This invention introduces polysiloxane segments into the polycarbonate molecular chain through copolymerization, resulting in a phosphorus-silicon copolymer polycarbonate with good resistance to chemical reagents and low-temperature impact resistance. Li Zhen et al. (Biomacromolecules 2018, 19, 2137−2145) introduced polysiloxanes as soft segments into polyurethane to improve its hydrolysis and oxidation resistance. Patent CN111748279A discloses a method for modifying polyethylene terephthalate with polysiloxane blocks and fluorinated glycols to prepare a modified polyester with high weather resistance and high stain resistance, which can be used in coatings and color-coated steel sheets.

[0005] Currently, there are no research reports on the preparation of block copolymers by introducing polysiloxane blocks into biodegradable polyester polybutylene succinate. Polybutylene succinate is generally prepared by esterification and polycondensation of succinic acid and butanediol, with water as a byproduct. Water easily causes crosslinking of the polysiloxane blocks, thereby reducing the surface functionality of the material. No solution to this problem has been provided in the literature.

[0006] In view of this, the present invention is proposed. Summary of the Invention

[0007] The purpose of this invention is to provide a polybutylene succinate and a polysiloxane block copolymer and a method for preparing the same, so as to solve the performance defects of polybutylene succinate products in the prior art.

[0008] To address the issue that esterification and polycondensation routes easily generate water as a byproduct, which can lead to crosslinking of polysiloxane blocks, this invention uses dimethyl succinate as a reactant and prepares block copolymers through transesterification and polycondensation. Because no water byproduct is generated, the degree of self-crosslinking of the polysiloxane blocks is significantly reduced, improving the surface functionality of the copolyester. The polybutylene succinate and polysiloxane block copolyester prepared by the method provided in this invention exhibit excellent mechanical properties, as well as good antifouling and self-cleaning functions.

[0009] Specifically, to solve the above-mentioned technical problems, the present invention provides a polybutylene succinate and polysiloxane block copolymer (PBS- b The method (-PDMS) includes the following steps:

[0010] (1) Dimethyl succinate, butanediol and polysiloxane are mixed and subjected to transesterification reaction in the presence of a transesterification catalyst to obtain transesterification products;

[0011] (2) The product of the above reaction is mixed with a polycondensation catalyst to carry out a polycondensation reaction, thereby obtaining the PBS- b -PDMS copolyester.

[0012] The polysiloxanes include polysiloxanes with different molecular chain lengths, ranging from 1000 to 12000 g / mol.

[0013] The polysiloxane includes one of polysiloxane PDMsa, polysiloxane PDMsb, and polysiloxane PDMsc.

[0014] The chemical structural formula of PDMSa is shown in formula (Ⅰ):

[0015]

[0016] Equation (I)

[0017] Where n is 20-120;

[0018] The chemical structural formula of PDMSb is shown in formula (II):

[0019]

[0020] Formula (II)

[0021] Where n is 10-80 and m is 4-10;

[0022] The chemical structural formula of PDMSc is shown in formula (Ⅲ):

[0023]

[0024] Formula (III)

[0025] Where n is 5-80 and m is 1-16.

[0026] The molar ratio of repeating units of the polysiloxane chain to dimethyl succinate units is 1:2.5-1:20.

[0027] The transesterification catalyst includes one or more of inorganic metal acetates, organotitanium compounds, and phosphorus-containing compounds.

[0028] The polycondensation catalyst comprises a mixture of phosphorus-containing compounds and organotitanium compounds.

[0029] The inorganic metal acetate includes one or more of antimony acetate, magnesium acetate, and zinc acetate;

[0030] The organotitanium compounds include alkyl titanium with a total carbon atom count of 4-40 and / or alkoxy titanium with a total carbon atom count of 4-40.

[0031] The phosphorus-containing compound includes one or more of phosphoric acid, trimethyl phosphate, triethyl phosphate, tributyl phosphate, and tripropyl phosphate.

[0032] Preferably, the mass of the transesterification catalyst is 0.002-3% of the sum of the masses of the dimethyl succinate and butanediol.

[0033] Preferably, when the transesterification catalyst is a mixture of inorganic acetate and organic titanium compound, the mass ratio of the inorganic acetate to the organic titanium compound is 0.2-1:1.

[0034] Preferably, when the polycondensation catalyst is a mixture of a phosphorus-containing compound and an organotitanium compound, the molar ratio of the phosphorus-containing compound to the organotitanium compound is 0.05-1.5:1.

[0035] Preferably, the mass of the polycondensation catalyst is 0.005-3% of the sum of the masses of dimethyl butanediol, butanediol, and polysiloxane.

[0036] Preferably, the molar ratio of dimethyl succinate to butanediol is 1:1 to 1:2.5.

[0037] Preferably, the transesterification reaction is carried out at a pressure of 10-120 kPa, a temperature of 110-190 °C, and a time of 1-3 h.

[0038] Preferably, the polycondensation reaction is carried out at a pressure of 20-500 Pa, a temperature of 170-250℃, and a time of 1-3 hours.

[0039] This invention also provides PBS prepared using the above-mentioned technical solution. b -PDMS copolyester, wherein the weight-average molecular weight of the block copolyester is greater than 200,000.

[0040] PDMS molecular chains diffuse into the surface and sublayers of materials, and accumulate on the material surface, undergo microphase separation, and self-crosslinking, thereby enabling PBS- b -PDMS copolyester possesses excellent mechanical properties, superior self-cleaning and anti-fouling capabilities, and the sample remains unbroken under impact, with an impact strength as high as 69.3 kJ / m. 2 With a tensile strength of up to 48.0 MPa, a flexural strength of up to 31.9 MPa, an elongation at break of up to 580.9%, and a static water contact angle of up to 117.3°, polybutylene succinate is endowed with functionality and its various mechanical properties are improved. Attached Figure Description

[0041] Figure 1 The polybutylene succinate and polysiloxane block copolyester PBS prepared in Example 1 b -A physical image of PDMS1.

[0042] Figure 2 The diagrams show the self-cleaning and anti-fouling test results of polybutylene succinate, polysiloxane block copolyester, and polybutylene succinate homopolymer prepared in Examples 1, 2, 2, 4, 4.1 and 4.2, and Comparative Example A. Detailed Implementation

[0043] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] The evaluation methods involved in the embodiments and comparative examples of this invention are as follows:

[0045] Molecular weight was determined by gel permeation chromatography (GPC), specifically using an Agilent Technologies 1260 Infinity with dichloromethane as the mobile phase, polystyrene as the standard, a flow rate of 1 mL / min, and column and chamber temperatures of 40 °C.

[0046] The actual content of polysiloxane blocks in the examples and comparative examples was tested by proton nuclear magnetic resonance spectroscopy. Specifically, Bruker AVIII400 NMR was used with CDCl3 as solvent and TMS as internal standard.

[0047] The mechanical properties of the samples prepared in the embodiments and comparative examples of this invention were tested as follows: tensile strength was tested according to GB / T1040.2-2006 Part 2: Test conditions for molding and extruded plastics; flexural strength was tested according to GB / T9341-2008 flexural performance test; intrinsic viscosity was tested according to the method specified in 5.1.1 of GB / T14190-2008.

[0048] The present invention also tested the surface wettability of the samples prepared in the examples and comparative examples, as follows: the static contact angle of water droplets on a flat polymer film was determined using a DSA10-MK2. For each sample film, at least five locations were measured. The test environment temperature was 25°C and the water droplet size was 0.5 µL.

[0049] The self-cleaning and anti-fouling properties of the examples and comparative samples in this invention are tested using the following methods:

[0050] (1) The test sample film is attached to a glass slide and tilted at a certain angle. Quartz sand is spread evenly on the surface of the film as a pollutant. Then, a few drops of water (a total of 2 mL) are dropped on the surface of the film, and the adsorption of quartz sand during the falling process is observed.

[0051] The tilt angle has little effect in this step. The experiment involves attaching the thin film material to a glass slide, which is then tilted at the edge of the petri dish. All test samples are kept at the same tilt angle. The main purpose is to compare the anti-fouling ability of the copolymer and homopolymer. The droplet sliding time and the amount of residual quartz sand are recorded and observed. The preferred angle is 30°.

[0052] (2) Using cola, milk, and ink as contaminants, drop them onto a sample film at a certain angle and observe the sliding speed of the contaminant droplets and the traces left by the sliding trajectory.

[0053] (3) Write on the sample film with a black marker, then wipe the writing marks with a paper towel and observe the writing marks remaining on the sample film.

[0054] Performance tests were conducted on the samples prepared according to the embodiments and comparative examples of the present invention, and the results are shown in the table below:

[0055] Example 1

[0056] This embodiment discloses a method for preparing polybutylene succinate and polysiloxane block copolymer, which includes the following steps:

[0057] Dimethyl succinate, butanediol, and PDMSa (molecular weight 3000 g / mol) (total mass 10 kg) were added to a reactor. The molar ratio of dimethyl succinate to butanediol was 1:2.0, and the molar ratio of repeating units to dimethyl succinate units in the polysiloxane block was 1:9. Then, 0.2 g of magnesium acetate (the transesterification catalyst was 0.0025% of the total mass of dimethyl succinate and butanediol) was added. The transesterification reaction was carried out at atmospheric pressure and 160 °C for 3 h. Then, the temperature was raised to 200 °C, and 5 g of tetrabutyl titanate and 0.8 g of phosphoric acid (the amount of phosphoric acid was about 0.63 times the amount of tetrabutyl titanate) were added. The pre-condensation reaction was carried out at 500 Pa and 210 °C for 1 h. The temperature was then raised to 220°C and the pressure was reduced to 50 Pa for a polycondensation reaction for 2 hours to obtain a block polymer of polybutylene succinate and polysiloxane, denoted as PBSP1.

[0058] Example 2

[0059] Example 2 included two experiments: Experiment 2.1 and Experiment 2.2.

[0060] The difference between Experiment 2.1 and Example 1 is that 4g of tetrabutyl titanate and 0.8g of phosphoric acid (the amount of phosphoric acid is 0.79 times the amount of tetrabutyl titanate) were added before the pre-condensation reaction to obtain PBSP2.

[0061] The difference between Experiment 2.2 and Example 1 is that 0.4g of magnesium acetate (the transesterification catalyst is 0.005% of the total mass of dimethyl succinate and butanediol) was added during the transesterification stage, and 10g of tetrabutyl titanate and 2.2g of phosphoric acid (the amount of phosphoric acid is about 0.87 times the amount of tetrabutyl titanate) were added before the pre-condensation reaction to obtain PBSP3.

[0062] Example 3

[0063] Example 3 included four experiments: Experiment 3.1, Experiment 3.2, Experiment 3.3, and Experiment 3.4.

[0064] The only difference between Experiment 3.1 and Example 1 is that the molecular weight of PDMSa is 1000 g / mol, and PBSP4 is finally obtained.

[0065] The only difference between Experiment 3.2 and Example 1 is that the molecular weight of PDMSa is 6000 g / mol, and PBSP5 is finally obtained.

[0066] The only difference between Experiment 3.3 and Example 1 is that the molecular weight of PDMSa is 8000 g / mol, and PBSP6 is finally obtained.

[0067] The only difference between Experiment 3.4 and Example 1 is that the molecular weight of PDMSa is 12000 g / mol, and PBSP7 is finally obtained.

[0068] Example 4

[0069] Example 4 consisted of five experiments: Experiment 4.1, Experiment 4.2, Experiment 4.3, Experiment 4.4, and Experiment 4.5.

[0070] The only difference between Experiment 4.1 and Example 3.2 is that the molar ratio of PDMsa repeating unit to dibutyl succinate repeating unit is 1:19, and PBSP8 is finally obtained.

[0071] The only difference between Experiment 4.2 and Example 3.2 is that the molar ratio of PDMsa repeating unit to dibutyl succinate repeating unit is 1.5:8.5, and PBSP9 is finally obtained.

[0072] The only difference between Experiment 4.3 and Example 3.2 is that the molar ratio of PDMsa repeating unit to dibutyl succinate repeating unit is 2:8, and PBSP10 is finally obtained.

[0073] The only difference between Experiment 4.4 and Example 3.2 is that the molar ratio of PDMsa repeating unit to dibutyl succinate repeating unit is 3:7, resulting in PBSP11.

[0074] The only difference between Experiment 4.5 and Example 2.2 is that the molar ratio of PDMSa repeating unit to dibutyl succinate repeating unit is 4:6, resulting in PBSP10.

[0075] Example 5

[0076] Example 5 consisted of five tests: 5.1, 5.2, 5.3, 5.4, and 5.5.

[0077] The only difference between Experiment 5.1 and Experiment 2.2 is that the polysiloxane block used is PDMSb, and the structural formula of the polysiloxane block used is shown in Formula (II), which finally yields PBSP12.

[0078] The only difference between Experiment 5.2 and Experiment 2.2 is that the polysiloxane block used is PDMSc, and the structural formula of the polysiloxane block used is shown in Formula (Ⅲ), which finally yielded PBSP13.

[0079] The only difference between Experiment 5.3 and Experiment 5.1 is that the molecular weight of the PDMSb used is 6000 g / mol, and PBSP14 is finally obtained.

[0080] The only difference between Experiment 5.4 and Experiment 5.2 is that the molecular weight of the PDMSc used is 8000 g / mol, and PBSP15 is finally obtained.

[0081] Example 6

[0082] Example 6 consisted of four tests: 6.1, 6.2, 6.3, and 6.4.

[0083] The only difference between Experiment 6.1 and Example 4.3 is that the transesterification reaction was carried out at atmospheric pressure and temperature of 170°C, while the polycondensation reaction was carried out at 100 Pa and temperature of 230°C, ultimately yielding PBSP16.

[0084] The only difference between Experiment 6.2 and Example 4.3 is that the transesterification reaction was carried out at atmospheric pressure and temperature of 180°C, while the polycondensation reaction was carried out at 20 Pa and temperature of 235°C, ultimately yielding PBSP17.

[0085] The only difference between Experiment 6.3 and Example 4.3 is that the transesterification reaction was carried out at atmospheric pressure and temperature of 155°C, while the polycondensation reaction was carried out at 80 Pa and temperature of 250°C, ultimately yielding PBSP18.

[0086] The only difference between Experiment 6.4 and Example 4.3 is that the transesterification reaction was carried out at atmospheric pressure and temperature of 175°C, while the polycondensation reaction was carried out at 120 Pa and temperature of 245°C, ultimately yielding PBSP19.

[0087] Example 7

[0088] Example 7 consisted of five tests: 7.1, 7.2, 7.3, 7.4, and 7.5.

[0089] The only difference between Experiment 7.1 and Experiment 2.1 is that the transesterification catalyst in the transesterification reaction was replaced with zinc acetate, and PBS20 was finally obtained.

[0090] The only difference between Experiment 7.2 and Experiment 2.1 is that the transesterification catalyst in the transesterification reaction is replaced with a mixture of magnesium acetate and tetrabutyl titanate (with a mass ratio of magnesium acetate to tetrabutyl titanate of 1:2), which ultimately yields PBS21.

[0091] The only difference between Experiment 7.3 and Experiment 2.1 is that the phosphoric acid in Example 1 was replaced with trimethyl phosphate (the amount of trimethyl phosphate was 1.5 times the amount of tetrabutyl titanate), and PBS22 was finally obtained.

[0092] The only difference between Experiment 7.4 and Experiment 2.1 is that the phosphoric acid in Example 1 was replaced with triphenyl phosphate (the amount of triphenyl phosphate was 1.0 times the amount of tetrabutyl titanate), and PBS23 was finally obtained.

[0093] The only difference between Experiment 7.5 and Experiment 2.1 is that tetrabutyl titanate in Example 1 is replaced with titanium glycolate (the amount of phosphate is 1.5 times the amount of titanium glycolate), and PBS24 is finally obtained.

[0094] Comparative Example

[0095] Two experiments were conducted for the comparative example: Experiment A and Experiment B.

[0096] The only difference between Experiment A and Example 1 is that polysiloxane blocks are not added to the transesterification stage system, resulting in PBS-A.

[0097] The only difference between Experiment B and Example 1 is that siloxane blocks are not added to the transesterification stage system, but siloxane blocks are added to the prepolymerization forward reactor. The molar ratio of repeating units to dimethyl succinate units in the polysiloxane blocks is 1:9, and PBSP-B is finally obtained.

[0098] Table 1 Performance test results of samples prepared in the examples and comparative examples

[0099] sample Mn (104 g / mol) Tensile strength (MPa) Elongation at break (%) Impact strength (kJ / m2) Bending strength (MPa) Contact angle (°) PBSP1 23.2 47.6 ± 3.1 508.3 ± 16.1 31.7 ± 1.0 27.9± 0.8 110.2 ± 3.7 PBSP2 23.4 47.9± 2.3 510.9 ± 7.2 32.7 ± 1.8 28.1± 1.4 110.4 ± 3.3 PBSP3 23.5 48.0± 4.1 514.1 ± 17.8 32.9 ± 1.1 28.3± 2.3 110.1 ± 1.8 PBSP4 22.3 46.9 ± 2.8 460.3 ± 7.7 26.2 ± 2.9 26.3± 1.8 106.9 ± 1.2 PBSP5 24.6 45.2 ± 3.7 526.3 ± 15.6 32.1 ± 0.8 28.5± 2.8 111.3± 0.9 PBSP6 24.8 43.2 ± 5.5 553.1 ± 7.9 34.0 ± 1.2 29.0± 0.9 116.0± 4.2 PBSP7 25.2 41.1 ± 4.9 580.9 ± 11.1 36.3 ± 2.3 29.7± 2.5 116.1± 1.3 PBSP8 23.4 44.6± 2.2 511.3 ±8.8 29.2 ± 1.9 26.8± 1.1 108.5± 2.0 PBSP9 25.0 46.6± 5.9 539.9 ±5.1 31.7 ± 1.0 28.9± 0.8 114.5± 1.4 PBSP10 25.6 45.5± 2.8 548.9 ±15.8 52.8 ± 2.5 29.3± 1.0 115.8± 3.2 PBSP11 25.8 45.1± 4.7 552.9 ±13.6 54.2 ± 1.7 30.4± 0.3 116.3± 2.9 PBSP12 26.6 44.5± 1.0 566.0 ±9.3 63.9± 3.3 28.9± 2.2 117.3± 4.6 PBSP13 20.3 41.1± 3.3 510.9±16.1 33.4 ± 4.2 27.1± 1.8 101.2±3.1 PBSP14 20.1 40.9± 5.2 490.9±9.3 33.8 ± 5.3 26.9± 0.9 100.8±2.0 PBSP15 20.2 40.6± 2.1 522.3±9.4 34.1± 1.2 26.8± 1.2 104.6±4.4 PBSP16 19.4 39.8± 3.2 510.2±7.3 32.8 ± 0.7 26.2± 3.3 105.6±0.9 PBSP17 25.8 45.4± 3.8 539.9 ± 6.9 52.8± 0.4 29.3± 0.5 116.8± 2.2 PBSP18 26.0 45.1± 1.7 546.2 ±7.5 53.2± 1.3 29.9± 1.6 115.8± 0.9 PBSP19 26.1 45.9± 1.4 532.9 ±17.8 51.2± 1.3 31.2± 2.2 116.0± 2.6 PBSP20 25.9 45.8± 5.8 562 ±11.3 51.3± 1.5 30.8± 1.3 115.7± 3.3 PBSP21 23.8 46.6 ± 2.1 502.3 ± 9.1 32.7 ± 1.1 31.3± 1.4 110.5 ± 3.1 PBSP22 24.1 47.3 ± 1.7 515.3 ±6.4 34.3 ± 2.3 31.9± 0.9 111.4 ± 1.6 PBSP23 23.9 46.8 ± 3.2 518.3 ± 17.5 31.3 ± 4.4 29.6± 0.8 109.4 ± 3.6 PBSP24 22.7 45.9± 4.1 498.3 ±8.5 30.3 ± 1.3 28.9± 2.1 112.6 ± 1.1 PBSP25 23.2 46.1 ± 1.8 500.3 ±4.5 31.2 ± 0.9 29.1± 0.5 110.0 ± 0.8 PBS-A 20.1 36.8± 2.6 410.1±3.3 7.8± 0.2 25.8± 0.3 86.3± 4.6 PBSP-B 21.3 40.2± 3.9 430.1±3.3 25.1 ± 2.0 26.7± 0.8 103.4± 1.6

[0100] The actual siloxane block content of the embodiments and comparative examples of the present invention is shown in the table below.

[0101] Table 2 Actual PDMS block content in samples prepared for examples and comparative examples

[0102] sample PBSP1 PBSP7 PBSP8 PBSP9 PBS-A PDMS content (mol%) 9.6 14.8 19.2 28.8 5.4

[0103] This application is attached Figure 1 The image shows a physical picture of the PBSP1 granules prepared in Example 1.

[0104] Appendix Figure 2 This study demonstrates how quartz sand powder, used as a contaminant, is evenly applied to the surface of a PBS copolyester film (adhered to a glass slide). Then, a few drops of water are dropped onto the film surface at a certain angle. The water droplets absorb the quartz sand as they slide, leaving clean traces along their path. However, a certain amount of quartz sand remains on the surface of the pure PBS film, indicating that the PBS copolyester possesses self-cleaning properties. Writing on the pure polybutylene succinate film with a marker shows that the increased PDMS block content in the block copolyester makes the film less prone to leaving writing marks after wiping. Furthermore, cola, milk, red ink, and black ink are dropped onto the surfaces of PBS and its copolyester film as contaminants to further investigate the self-cleaning properties of the polybutylene succinate copolyester. These droplets leave traces on the pure PBS surface and slide down slowly, indicating that droplets such as milk easily contaminate the film surface. However, with the increase of PDMS segment content, the droplet sliding speed on the block copolymer film increased significantly, and no trace was left during the sliding process, indicating that PDMS blocks significantly improved the self-cleaning and liquid-resistant properties of polybutylene succinate.

[0105] As can be seen from the table above, the block copolyester material prepared by this invention has excellent mechanical properties, as well as good anti-fouling and self-cleaning functions.

[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing polybutylene succinate and polysiloxane block copolymer, characterized in that, Includes the following steps: (1) Dimethyl succinate, butanediol and polysiloxane are mixed and subjected to transesterification reaction in the presence of a transesterification catalyst to obtain transesterification products; (2) The product of the above reaction is mixed with a polycondensation catalyst and polycondensation reaction is carried out to obtain a block copolymer; The polysiloxane blocks include polysiloxanes with different molecular chain lengths, ranging from 1000 to 12000 g / mol. The transesterification catalyst comprises one or more of inorganic metal acetates, organotitanium compounds, and phosphorus-containing compounds; the polycondensation catalyst comprises a mixture of phosphorus-containing compounds and organotitanium compounds; the mass of the transesterification catalyst is 0.002-3% of the sum of the masses of dimethyl succinate and butanediol; the mass of the polycondensation catalyst is 0.005-3% of the sum of the masses of dimethyl butanediol, butanediol, and polysiloxane; the polysiloxane comprises one of polysiloxane PDMSa, polysiloxane PDMSb, and polysiloxane PDMSC, and the chemical structural formula of PDMSa is shown in Formula (I): Equation (I) Where n is 10-120; the chemical structural formula of PDMSb is shown in formula (II): Formula (II) Where n is 10-80 and m is 4-10; The chemical structural formula of PDMSc is shown in formula (Ⅲ): Formula (III) Where n is 5-80 and m is 1-16.

2. The preparation method according to claim 1, characterized in that, In the block copolymer, the molar ratio of repeating polysiloxane segments to dimethyl succinate segments is 1:2.5-1:

20.

3. The preparation method according to claim 1, characterized in that, The inorganic metal acetate includes one or more of antimony acetate, magnesium acetate, and zinc acetate; the organotitanium compound includes alkyl titanium with a total carbon atom count of 4-40 and / or alkoxy titanium with a total carbon atom count of 4-40; the phosphorus-containing compound includes one or more of phosphoric acid, trimethyl phosphate, triethyl phosphate, tributyl phosphate, and tripropyl phosphate.

4. The preparation method according to claim 1, characterized in that, When the transesterification catalyst is a mixture of inorganic acetate and organic titanium compound, the mass ratio of the inorganic acetate to the organic titanium compound is 0.2-1:1; when the polycondensation catalyst is a mixture of phosphorus-containing compound and organic titanium compound, the molar ratio of the phosphorus-containing compound to the organic titanium compound is 0.05-1.5:

1.

5. The preparation method according to claim 1, characterized in that, The molar ratio of dimethyl succinate to butanediol is 1:1 to 1:2.

5.

6. The preparation method according to claim 1, characterized in that, The transesterification reaction is carried out at a pressure of 10-120 kPa, a temperature of 110-190 °C, and a time of 1-3 h; the polycondensation reaction is carried out at a pressure of 20-500 Pa, a temperature of 170-250 °C, and a time of 1-3 h.

7. A polybutylene succinate and polysiloxane block copolymer prepared by the preparation method according to any one of claims 1-6, characterized in that, The block copolymer is a block copolyester, and the weight-average molecular weight of the block copolyester is greater than 200,000.

Images